<template>
    <div class="type-nav">
        <div class="container">
            <div @mouseleave="leaveShow"  @mouseenter="enterShow">
                <h2 class="all">全部商品分类</h2>
                <div class="sort" v-show="show">
                    <div class="all-sort-list2" @click="goSearch">
                        <div class="item" v-for="(item1, index) in categoryList" :key="item1.categoryId"
                            :class="{ active: currentIndex == index }">
                            <h3 @mouseenter="changeIndex(index)">
                                <a :data-categoryName="item1.categoryName" :data-category1Id="item1.categoryId">{{ item1.categoryName }}</a>
                            </h3>
                            <div class="item-list clearfix">
                                <div class="subitem" v-for="(item2) in item1.categoryChild" :key="item2.categoryId">
                                    <dl class="fore">
                                        <dt>
                                            <a :data-categoryName="item2.categoryName" :data-category2Id="item2.categoryId">{{ item2.categoryName }}</a>
                                        </dt>
                                        <dd>
                                            <em v-for="(item3) in item2.categoryChild" :key="item3.categoryId">
                                                <a :data-categoryName="item3.categoryName" :data-category3Id="item3.categoryId">{{ item3.categoryName }}</a>
                                            </em>
                                        </dd>
                                    </dl>
                                </div>
                            </div>
                        </div>
                    </div>
                </div>
            </div>
            <nav class="nav">
                <a href="###">服装城</a>
                <a href="###">美妆馆</a>
                <a href="###">尚品汇超市</a>
                <a href="###">全球购</a>
                <a href="###">闪购</a>
                <a href="###">团购</a>
                <a href="###">有趣</a>
                <a href="###">秒杀</a>
            </nav>

        </div>
    </div>
</template>
<script>
import { mapState } from 'vuex'
//引入方式  是把lodash全局功能引
import throttle from 'lodash/throttle'
export default {
    name: 'TypeNav',
    props: {},
    components: {},
    data() {
        return {
            //储存用户鼠标移动到哪一个一级分类
            currentIndex: -1,
            //默认隐藏
            show:true
        };
    },
    watch: {},
    methods: {
        //鼠标进入修改响应式数据currentIndex属性
        // changeIndex(index) {
        //     //console.log('鼠标进入'+index);
        //     //index：鼠标移动到某一个一级分类的元素的索引值
        //     //正常情况（用户慢慢操作）：鼠标进入 每一个一级分类h3  都被触发
        //     //非正常情况（用户操作很快）：本身全部的一级分类都应该进入事件   但是经过测试只有h3部分触发
        //     //就是由于用户行为过快  导致浏览器反应不过来   如果当回调函数中有一些大量的业务   有可能会出现卡顿现象
        //     this.currentIndex = index;
        // }
        //节流
        changeIndex:throttle(function(index){
            this.currentIndex = index;
        },50),
        //跳转到Search
        goSearch(event){
            let element = event.target;
            let {categoryname,category1id,category2id,category3id} = element.dataset;
            if(categoryname){
                //整理路由跳转的参数
                //要跳转的路由
                let location = {name:'search'}
                //跳转的标签和id值
                let query = {categoryName:categoryname};
                if(category1id){
                    query.category1Id = category1id;
                }else if(category2id){
                    query.category2Id = category2id;
                }else if(category3id){
                    query.category3Id = category3id;
                }
                location.params = this.$route.params
                location.query = query;
                this.$router.push(location);

            }
        },
        //鼠标进入时显示
        enterShow(){
            this.show = true;
        },
        //鼠标离开事件
        leaveShow(){
            this.currentIndex = -1;
            if(this.$route.path != '/home'){
                this.show = false;
            }
        }
    },
    created() { },
    mounted() {
        if(this.$route.path != '/home'){
            this.show = false
        }
    },
    beforeDestroy() { },
    computed: {
        ...mapState('home',['categoryList'])
    }
};
</script>
<style lang='less' scoped>
.active {
    background-color: skyblue;
}

.type-nav {
    border-bottom: 2px solid #e1251b;

    .container {
        width: 1200px;
        margin: 0 auto;
        display: flex;
        position: relative;

        .all {
            width: 210px;
            height: 45px;
            background-color: #e1251b;
            line-height: 45px;
            text-align: center;
            color: #fff;
            font-size: 14px;
            font-weight: bold;
        }

        .nav {
            a {
                height: 45px;
                margin: 0 22px;
                line-height: 45px;
                font-size: 16px;
                color: #333;
            }
        }

        .sort {
            position: absolute;
            left: 0;
            top: 45px;
            width: 210px;
            height: 461px;
            position: absolute;
            background: #fafafa;
            z-index: 999;

            .all-sort-list2 {
                .item {
                    h3 {
                        line-height: 30px;
                        font-size: 14px;
                        font-weight: 400;
                        overflow: hidden;
                        padding: 0 20px;
                        margin: 0;

                        a {
                            color: #333;
                        }
                    }

                    .item-list {
                        display: none;
                        position: absolute;
                        width: 734px;
                        min-height: 460px;
                        background: #f7f7f7;
                        left: 210px;
                        border: 1px solid #ddd;
                        top: 0;
                        z-index: 9999 !important;

                        .subitem {
                            float: left;
                            width: 650px;
                            padding: 0 4px 0 8px;

                            dl {
                                border-top: 1px solid #eee;
                                padding: 6px 0;
                                overflow: hidden;
                                zoom: 1;

                                &.fore {
                                    border-top: 0;
                                }

                                dt {
                                    float: left;
                                    width: 54px;
                                    line-height: 22px;
                                    text-align: right;
                                    padding: 3px 6px 0 0;
                                    font-weight: 700;
                                }

                                dd {
                                    float: left;
                                    width: 415px;
                                    padding: 3px 0 0;
                                    overflow: hidden;

                                    em {
                                        float: left;
                                        height: 14px;
                                        line-height: 14px;
                                        padding: 0 8px;
                                        margin-top: 5px;
                                        border-left: 1px solid #ccc;
                                    }
                                }
                            }
                        }
                    }

                    &:hover {
                        .item-list {
                            display: block;
                        }
                    }
                }
            }
        }
    }
}
</style>